Semiconductor element holding apparatus and semiconductor device manufactured using the same

ABSTRACT

A semiconductor element holding apparatus includes a collet for suctioning a semiconductor element by negative pressure to hold the semiconductor element. The collet has a protrusion formed at the semiconductor element-holding surface thereof, and the protrusion is provided with a plurality of suction holes. The suction holes are opened to the semiconductor element-holding surface. The surface of the semiconductor element is held by the semiconductor element-holding surface of the protrusion of the collet.

This is a Divisional of U.S. application Ser. No. 11/178,467, filed Jul.12, 2005, and issued as U.S. Pat. No. 7,207,554 on Apr. 24, 2007, thesubject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor element holdingapparatus that is capable of holding and conveying one or moresemiconductor elements separated from a wafer to a desired place, andalso relates to a semiconductor device manufactured using the same.

2. Description of the Related Art

A conventional semiconductor element holding apparatus fixes a waferhaving a plurality of semiconductor elements formed thereon to a sheeton which an adhesive agent is applied. Then, the wafer is divided intopieces (i.e., a plurality of semiconductor elements) by a cutter. Thesemiconductor element holding apparatus raises one of the dividedsemiconductor elements by means of lifting needles, and suctions theraised semiconductor element to the inclined surface of a collet havingan inclined suctioning part by negative pressure. In this way, theconventional semiconductor element holding apparatus holds thesemiconductor element. This is for example, disclosed in a JapanesePatent Kokai (Laid-open Application) No. 5-326673.

When the semiconductor element has an area whose surface can not bebrought into direct contact with the collet of the semiconductor elementholding apparatus (e.g., when the semiconductor element is a chargecoupled device (CCD)), surface contact areas are formed on both ends inthe lengthwise direction of the semiconductor element, and the surfacecontact areas are brought into contact with a collet having vacuumsuction holes so that the semiconductor element is suctioned, and held,by the negative pressure applied from the vacuum suction holes of thecollet. This is for example disclosed in a Japanese Patent Kokai(Laid-open Application) No. 5-243375.

Generally, a wafer having a plurality of semiconductor elements formedthereon is divided into pieces by a cutter, such as a diamond blade.When the wafer is cut by the cutter, the cut surface of each dividedsemiconductor element is partially collapsed due to minute scratches andcracks created when cutting the wafer. As a result, a fragile layer of 5to 10 μm (hereinafter, referred to as an “element collapse layer”) isformed.

According to Japanese Patent Kokai No. 5-326673, the semiconductorelement divided from the wafer is suctioned to the inclined surface ofthe collet. When the inclined surface of the collet is brought intocontact with the edge of the cut surface of the semiconductor element,the element collapse layer is collapsed. As a result, pieces of thecollapsed element collapse layer (hereinafter, referred to as “elementcollapse pieces”) drop onto other semiconductor elements when thesemiconductor element is suctioned by the collet or the semiconductorelement is released after conveying the semiconductor to a remote place.Consequently, the cleanness of the semiconductor element isdeteriorated.

In a semiconductor element having flexible parts that are thin to haveflexibility, such as a semiconductor element used in a semiconductoracceleration sensor, the flexible parts are deformed and thus damagedwhen the inclined surface of the collet is brought into contact with theedge of the semiconductor element to suction the entire surface of thesemiconductor element by negative pressure.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an arrangement forpreventing creation of element collapse pieces in a semiconductorelement having an element collapse layer formed thereon.

Another object of the present invention is to provide an arrangement forpreventing damage to flexible parts in a semiconductor element havingthe flexible parts.

According to one aspect of the present invention, there is provided animproved semiconductor element holding apparatus. This semiconductorelement holding apparatus includes a collet for suctioning asemiconductor element by negative pressure to hold the semiconductorelement. The collet has a protrusion formed at the semiconductorelement-holding surface thereof, and the protrusion is provided with aplurality of suction holes. The suction holes are directed to thesemiconductor element which is to held on the semiconductor-elementholding surface. The suction holes define, in effect, the semiconductorholding surface of the collet.

The semiconductor element-holding surface of the protrusion of thecollet is brought into contact with the surface of the semiconductorelement to hold the semiconductor element, and the collet does not comeinto contact with the element collapse layer formed at the cut surfaceof the semiconductor element. Consequently, the element collapse piecesare prevented from being created.

If the semiconductor element has flexible parts, the semiconductorelement is suctioned, and held, by the suction holes of the protrusionof the collet while the flexible parts of the semiconductor element areprotected by the semiconductor element-holding surface of theprotrusion. Consequently, the flexible parts of the semiconductorelement are prevented from being damaged.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, aspects and advantages of thepresent invention will be more clearly understood from the followingdetailed description and appended claims when taken in conjunction withthe accompanying drawings, in which:

FIG. 1 shows a semiconductor element holding apparatus according to afirst embodiment of the present invention;

FIG. 2 is a bottom view of a collet of the semiconductor element holdingapparatus shown in FIG. 1;

FIG. 3 illustrates a cross-sectional view taken along line III-III ofFIG. 2;

FIG. 4 illustrates a cross-sectional view taken along line IV-IV of FIG.2;

FIG. 5 is a plan view of a semiconductor element used in a semiconductoracceleration sensor;

FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is an enlarged view of a collet and a semiconductor elementhaving flexible parts in a held state;

FIG. 8 is a bottom view showing a collet according to a secondembodiment of the present invention; and

FIG. 9 illustrates a cross-sectional view taken along line IX-IX of FIG.8.

DETAILED DESCRIPTION OF THE INVENTION

Now, semiconductor element holding apparatuses according to embodimentsof the present invention will be described in detail with reference tothe accompanying drawings.

Embodiment 1

Referring to FIG. 1, a semiconductor element holding apparatus accordingto a first embodiment of the present invention will be described.

The semiconductor element holding apparatus, which is indicated byreference numeral 1, includes a collet 2, a suction pump (not shown), acollet lifting mechanism and a collet X-Y moving mechanism. Thesemechanisms lift and move the collet 2 in X and Y directions.

The collet 2 has a surface facing a semiconductor element 3, which isheld by the collet 2. The semiconductor element-facing surface of thecollet 2 is formed in the shape similar to a surface 4 of thesemiconductor element 3. In the illustrated embodiment, thesemiconductor element-facing surface of the collet 2 is approximatelyformed in the shape of a rectangle, as shown in FIG. 2.

The semiconductor element 3 is divided from a wafer. The wafer is madeof silicon and has a plurality of semiconductor elements 3, such aslarge-scale integrated semiconductor elements. The lower surface of thewafer is fixed to a fixing sheet 5, on which an adhesive agent isapplied. The fixing sheet 5 has elasticity. The wafer is cut lengthwiseand breadthwise by a cutter, such as a diamond blade, into pieces.

Reference numeral 6 indicates lifting needles, which are verticallymovable to raise the divided semiconductor element 3 from the fixingsheet 5 to the collet 2.

Referring to FIG. 2, reference numeral 11 indicates a plurality ofsuction holes. The suction holes 11 are formed in a narrow protrusion,which is disposed at the semiconductor element-facing surface of thecollet 2, i.e., the semiconductor element-holding surface of the collet2. The suction holes 11 are opened to a semiconductor element-facingsurface 12 of the protrusion (hereinafter, referred to as a“semiconductor element-holding surface”).

In the illustrated embodiment, the protrusion includes a middleprotrusion part 13 disposed along the middle line of the semiconductorelement 3. The protrusion also includes two edge protrusion parts 14disposed along the breadthwise edges of the semiconductor element 3. Thecenter portions of the edge protrusion parts 14 are connected to bothends of the middle protrusion part 13, respectively. The edge protrusionparts 14 are at right angles to the middle protrusion part 13.Consequently, the protrusion is approximately formed in the shape of an“H.”

The semiconductor element-holding surface 12 of the protrusion isprocessed by a mirror finishing process or coated withpolytetrafluoroethylene.

Referring to FIGS. 1 and 3, reference numeral 15 indicates a middlenegative pressure channel 15, which extends through the collet 2 alongthe middle of the collet 2. The middle negative pressure channel 15 isdisposed above the middle protrusion part 13. The middle negativepressure channel 15 communicates with a negative pressure supply hole16, which is connected to the suction pump for supplying negativepressure to the collet 2. Also, the middle negative pressure channel 15communicates with the suction holes 11 opened to the semiconductorelement-holding surface 12 of the middle protrusion part 13.

Referring to FIG. 1 and FIG. 4, reference numeral 17 denotes edgenegative pressure channels, which extend through the collet 2 along bothedges of the collet 2. The edge negative pressure channels 17 aredisposed above the edge protrusion parts 14, respectively. The centerportions of the edge negative pressure channels 17 communicate with themiddle negative pressure channel 15. The edge negative pressure channels17 also communicate with the suction holes 11 opened to thesemiconductor element-holding surface 12 of the corresponding edgeprotrusion parts 14.

Referring back to FIG. 1 and FIG. 2, reference numeral 18 denotes caps,which are forcibly fitted in both ends of the middle negative pressurechannel 15 and both ends of the respective edge negative pressurechannels 17, respectively, for preventing air from leaking into thenegative pressure of the middle negative pressure channel 15 and theedge negative pressure channels 17. The lower right part of FIG. 2particularly shows the cap.

Consequently, the negative pressure supplied into the negative pressuresupply hole 16 is introduced into the respective suction holes 11through the middle negative pressure channel 15 and the edge negativepressure channels 17. As a result, when the semiconductorelement-holding surface 12 of the middle protrusion part 13 and the edgeprotrusion parts 14 come into contact with the surface 4 of thesemiconductor element 3, the semiconductor element 3 is held by suctionto the semiconductor element-holding surface 12. In this way, thesemiconductor element 3 is held by the semiconductor element holdingapparatus 1.

The height of the protrusion is set to a predetermined size S, which isindicated in FIGS. 3 and 4. Consequently, when the semiconductorelement-holding surface 12 of the protrusion comes into contact with thesurface 4 of the semiconductor element 3, a gap, which corresponds tothe size S, is formed between the surface 4 of the semiconductor element3 and the lower surface 19 of a main body of the collet 2.

In the illustrated embodiment, the size S is set to 0.05-0.3 mm, thediameter of the negative pressure supply hole 16 to 1.2-1.8 mm, thediameters of the middle negative pressure channel 15 and the edgenegative pressure channels 17 to 0.8-1.0 mm, the diameter of eachsuction hole 11 to 0.1-0.2 mm, the depth of each suction hole 11 to1.0-1.5 mm, the pitch between adjacent suction holes 11 to 0.5-0.7 mm,and the widths of the middle protrusion part 13 and the edge protrusionparts 14 to 0.3-0.5 mm. Such dimensions are suitable to hold thesemiconductor element 3 that is approximately formed in the shape of arectangle whose sides have lengths greater than 1.8 mm.

After the semiconductor element 3 is separated from the wafer on thefixing sheet 5 by the cutter, the semiconductor element 3 is held by thesemiconductor element holding apparatus 1 in the following manner. Inorder to hold the semiconductor element 3 by the semiconductor elementholding apparatus 1 having the collet 2 constructed as described above,as shown in FIG. 1, the upper ends of the lifting needles 6 are broughtinto contact with the lower surface of the semiconductor element 3, thelifting needles 6 are moved up through the fixing sheet 5 to separatethe semiconductor element 3 from the adhesive agent applied to thefixing sheet 5, the semiconductor element-holding surface 12 of thecollet 2 of the semiconductor element holding apparatus 1 is broughtinto contact with the surface 4 of the semiconductor element 3, and thenegative pressure is supplied into the negative pressure supply hole 16and then into the respective suction holes 11 through the middlenegative pressure channel 15 and the edge negative pressure channels 17.The suction holes 11 are opened in the semiconductor element-holdingsurface 12 so that the negative pressure generates a suction force, bywhich the middle part and the breadthwise edge parts of the surface 4 ofthe semiconductor element 3 are suctioned.

The semiconductor element 3 held by the suction is individually conveyedto a chip tray, a lead frame or a board by the lifting mechanism and/orthe X-Y moving mechanism of the semiconductor element holding apparatus1, and then the negative pressure is, released. As a result, thesemiconductor element 3 is disposed on the chip tray, the lead frame orthe board.

In the illustrated embodiment, the protrusion is disposed at thesemiconductor element-facing surface of the collet, i.e., thesemiconductor element-holding surface of the collet, and the suctionholes formed in the protrusion are opened to the semiconductor elementto form the holding surface at the protrusion. As a result, the holdingsurface of the protrusion of the collet can contact the surface of thesemiconductor element to hold the semiconductor element, and the colletdoes not come into contact with an element collapse layer formed at thecut surface of the semiconductor element. Consequently, element collapsepieces are prevented from being produced, and therefore, cleanness ofthe semiconductor element is maintained during and after conveying thesemiconductor element.

Also, the holding surface of the protrusion is processed by a mirrorfinishing process or coated with polytetrafluoroethylene. Consequently,when the holding surface of the protrusion of the collet 2 is broughtinto contact with the surface of the semiconductor element 3 tosuction-hold the semiconductor element 3, the surface of thesemiconductor element 3 is prevented from being damaged.

In addition, the protrusion is approximately formed in the shape of an“H,” and the semiconductor element 3 is suctioned to the holding surfaceof the “H”-shaped protrusion. Consequently, the stability of the holdingforce applied to the semiconductor element 3 is improved, and accuracyof the holding position between the semiconductor element 3 and thecollet 2 is ensured.

The collet 2 having the above-described “H”-shaped protrusion issuitable to hold a semiconductor element having flexible parts, such asa semiconductor element used in a semiconductor acceleration sensor,which will be described below with reference to FIG. 5 to FIG. 7.

FIG. 5 is a plan view showing a semiconductor element 21 used in asemiconductor acceleration sensor. This semiconductor element 21 hasflexible parts 26. FIG. 6 is a sectional view taken along line VI-VI inFIG. 5. FIG. 7 illustrates the semiconductor element which is in a heldstate.

Referring to FIGS. 5 and 6, reference numeral 22 indicates a chip bodyof the semiconductor element 21, which is divided from a wafer. At thechip body 22 are formed weight parts 24, flexible parts 26, measuringelements P, and chip electrodes 27. The weight parts 24 areapproximately cut off in the shape of a four-leafed clover by slits 23.The slits 23 are formed at the center area of the chip body 22 by ananisotropic etching process. The flexible parts 26 are defined by boreparts 25 formed in bridge parts between the adjacent weight parts 24.Each of the flexible parts 26 has a small thickness such that eachflexible part 26 has flexibility. Bridge circuits of a piezoelectricresistance element are formed in the flexible parts 26 by adding anddiffusing impurities in the flexible parts 26. The measuring elements Pare provided for measuring displacement of the flexible parts 26 asacceleration through the use of the change of electric characteristicsof the flexible parts 26. The chip electrodes 27 are internallyconnected to the measuring elements P.

Reference numeral 28 indicates a glass sheet, which is attached to thelower surface of the chip body 22 for restricting the amplitude of theflexible parts 26 due to the acceleration by a gap formed between thesurface of the glass sheet 28 and the surface of the weight part 24.This prevents the flexible parts 26 from being damaged.

The semiconductor element 21 is divided from the wafer, which is fixedto the glass sheet 28. Consequently, the collet 2 suctions thesemiconductor element 21 having the chip body 22 attached to the glasssheet 28 to hold the semiconductor element 21 as shown in FIG. 7.

The semiconductor element 21 has the flexible parts 26 as shown in FIG.7. However, the semiconductor element-holding surface 12 of the middleprotrusion part 13 of the collet 2 is brought into contact with thesurfaces of the flexible parts 26, and the surface 4 of thesemiconductor element 21 is suctioned by the suction holes 11 whosediameter is relatively small. Consequently, the deformation of theflexible parts 26 is effectively prevented by the semiconductorelement-holding surface 12 of the middle protrusion part 13 of thecollet 2 when a suction force is applied to the flexible parts 26, andtherefore, the flexible parts 26 are protected.

When holding the semiconductor element having the flexible parts, suchas a semiconductor element used in a semiconductor acceleration sensor,the collet 2 having the “H”-shaped protrusion shown in FIG. 2pneumatically holds the semiconductor element through the suction holeswhile protecting the flexible parts of the semiconductor element withthe holding surface of the protrusion, and therefore, the flexible partsof the semiconductor element are prevented from damaged.

Embodiment 2

A second embodiment will be described with reference to FIG. 8 and FIG.9.

FIG. 8 is a bottom view showing a collet 2′ according to a secondembodiment of the present invention, and FIG. 9 is a sectional viewtaken along line IX-IX of FIG. 8. Similar components of thesemiconductor element holding apparatus in the first and secondembodiments are assigned similar reference numerals and symbols, and adetailed description thereof will not be given below.

A semiconductor element used in the description of the semiconductorelement holding apparatus according to the second embodiment is thesemiconductor element 21 having the flexible parts 26, as described inconnection with FIG. 5 to FIG. 7.

As shown in FIGS. 8 and 9, the collet 2′ has a turned truncated coneshape whose diameter is gradually decreased toward the semiconductorelement 21. At the rear surface 19 of a main body of the collet 2′ isformed a frame-shaped protrusion having four edge protrusion parts 14,which correspond to four edges of the semiconductor element 21,respectively.

At each of the edge protrusion parts 14 are formed a plurality ofsuction holes 11, which are opened to the semiconductor element-holdingsurface 12. The suction holes 11 directly communicate with the negativepressure supply hole 16. The semiconductor element-holding surface 12 isprocessed by a mirror finishing process or coated withpolytetrafluoroethylene.

In the second embodiment, the size S, which is the height of theprotrusion, is set to 0.05-0.3 mm, the diameter of the negative pressuresupply hole 16 to 1.2-1.8 mm, the diameter of each suction hole 11 to0.05-0.2 mm, the depth of each suction hole 11 to 1.0-1.5 mm, the pitchbetween adjacent suction holes 11 to 0.5-0.7 mm, and the widths of thefour edge protrusion parts 14 to 0.3-0.5 mm. The widths of the four edgeprotrusion parts 14 are determined such that the areas of thesemiconductor element 21 having widths of 0.3 to 0.5 mm from the endsurfaces of the semiconductor element 21 are suctioned. These dimensionsare suitable to hold the semiconductor element 21 that is approximatelyformed in the shape of a square whose sides have lengths less than 1.8mm.

In order to suction and convey the semiconductor element 21 by thesemiconductor element holding apparatus 1 having the collet 2′, thesemiconductor element 21 is separated from the fixing sheet 5 by thelifting needles 6, the semiconductor element-holding surface 12 of thecollet 2′ of the semiconductor element holding apparatus 1 is broughtinto contact with the surface 4 of the semiconductor element 21, and thenegative pressure supplied into the negative pressure supply hole 16 issupplied into the respective suction holes 11. The negative pressuregenerates a suction force, by which the four edges of the surface 4 ofthe semiconductor element 21 are suctioned. In this way, thesemiconductor element 21 is held by the semiconductor element holdingapparatus 1.

Center parts of the semiconductor element-holding surface 12 are broughtinto contact with the flexible parts 26 of the semiconductor element 21.However, the suction holes 11 to suction the surface 4 of thesemiconductor element 21 are disposed outside the flexible parts 26.Consequently, the suction force is prevented from being applied to theflexible parts 26.

As shown in FIG. 9, the semiconductor element 21 held by the suction isindividually conveyed to a chip tray, a lead frame or a board by thelifting and X-Y moving mechanisms of the semiconductor element holdingapparatus 1, and then the negative pressure is released. As a result,the semiconductor element 21 is disposed on a desired location (the chiptray, the lead frame or the board).

The second embodiment can achieve the same advantages as the firstembodiment, and can also achieve additional advantages. Specifically,the protrusion has a frame shape (or rectangular shape), and the holdingsurface of the protrusion is brought into contact with the surface ofthe semiconductor element to suction the semiconductor element in thesecond embodiment. Consequently, the stability of the holding force ofthe semiconductor element is improved, and positional errors areeffectively prevented when the apparatus suctions the semiconductorelement.

When the semiconductor element having the flexible parts is held, thesurface of the semiconductor element outside the flexible parts issuctioned by the suction holes formed at the protrusion and thesemiconductor element is held by the semiconductor element holdingapparatus. Consequently, the flexible parts of the semiconductor elementare more reliably prevented from being damaged.

It should be noted that the embodiments of the present invention havebeen disclosed for illustrative purposes. Those skilled in the art willappreciate that various changes, modifications, additions andsubstitutions are possible, without departing from the scope and spiritof the invention as disclosed in the accompanying claims.

This application is based on a Japanese Patent Application No.2004-256391 filed on Sep. 3, 2004, and the entire disclosure thereof isincorporated herein by reference.

1. A method of manufacturing an acceleration sensor comprising:providing a collet which can apply a negative pressure, the collethaving a protrusion extending from a main body of the collet such thatthe protrusion defines a chip-holding surface of the collet, and aplurality of suction holes being formed in the protrusion such that theplurality of suction holes are opened in the chip-holding surface;providing a wafer having a plurality of acceleration sensor chips;cutting an acceleration sensor chip from the wafer; and lifting theacceleration sensor chip which has been cut from the wafer, by using thecollet which applies the negative pressure onto the acceleration sensorchip concerned, wherein the acceleration sensor chip includes a frameportion, a plurality of flexible arm portions extending inward from theframe portion and a weight portion supported by the plurality offlexible arm portions, and the collet applies the negative pressure tothe frame portion, the plurality of flexible arm portions and/or weightportion.
 2. The method as set forth in claim 1, wherein the protrusionincludes a middle protrusion part disposed along a center line of theacceleration sensor chip, and edge protrusion parts disposed along edgesof the acceleration sensor chip, the edge protrusion parts beingconnected to both ends of the middle protrusion part, respectively. 3.The method as set forth in claim 2, wherein the middle protrusion partapplies the negative pressure onto the weight portion and at least oneof the plurality of flexible arm portions of the acceleration sensorchip, and the edge protrusion parts apply the negative pressure onto theframe portion of the acceleration sensor chip.
 4. A method ofmanufacturing an acceleration sensor comprising: providing a colletwhich can apply a negative pressure, the collet having a protrusionextending from a main body of the collet such that the protrusiondefines a chip-holding surface of the collet, and a plurality of suctionholes being formed in the protrusion such that the plurality of suctionholes are opened in the chip-holding surface; providing a wafer having aplurality of acceleration sensor chips; cutting an acceleration sensorchip from the wafer; and lifting the acceleration sensor chip which hasbeen cut from the wafer, by using the collet which applies the negativepressure onto the acceleration sensor chip concerned, wherein saidproviding a collet includes processing the chip-holding surface of thecollet by a mirror finishing process.
 5. The method as set forth inclaim 4, wherein the acceleration sensor chip has a square orrectangular shape, and the protrusion includes four edge protrusionparts disposed along four edges of the acceleration sensor chip,respectively.
 6. The method as set forth in claim 5, wherein the colletapplies the negative pressure onto the four edges of the accelerationsensor chip.
 7. The method as set forth in claim 2, wherein the edgeprotrusion parts are at right angles to the middle protrusion part.
 8. Amethod of manufacturing an acceleration sensor comprising: providing acollet which can apply a negative pressure, the collet having aprotrusion extending from a main body of the collet such that theprotrusion defines a chip-holding surface of the collet, and a pluralityof suction holes being formed in the protrusion such that the pluralityof suction holes are opened in the chip-holding surface; providing awafer having a plurality of acceleration sensor chips; cutting anacceleration sensor chip from the wafer; and lifting the accelerationsensor chip which has been cut from the wafer, by using the collet whichapplies the negative pressure onto the acceleration sensor chipconcerned, wherein said providing a collet includes coating thechip-holding surface of the collet with polytetrafluoroethylene.
 9. Amethod of manufacturing an acceleration sensor comprising: providing acollet which can apply a negative pressure, the collet having aprotrusion extending from a main body of the collet such that theprotrusion defines a chip-holding surface of the collet, and a pluralityof suction holes being formed in the protrusion such that the pluralityof suction holes are opened in the chip-holding surface; providing awafer having a plurality of acceleration sensor chips; cutting anacceleration sensor chip from the wafer; and lifting the accelerationsensor chip which has been cut from the wafer, by using the collet whichapplies the negative pressure onto the acceleration sensor chipconcerned, wherein the acceleration sensor chip includes a frame portionhaving four linear edges, four flexible arm portions extending inwardfrom the four linear edges of the frame portion respectively, and aweight portion supported by the four flexible arm portions, and theprotrusion includes four edge protrusion parts disposed linearly alongthe four linear edges of the frame portion, respectively, such that thecollet applies the suction force only on the four linear edges of theframe portion.
 10. The method as set forth in claim 9, wherein saidproviding a wafer includes making the four flexible arm portions thinnerthan the frame portion.
 11. The method as set forth in claim 4, whereinthe chip-holding surface of the collet extends along an outer peripheryof the acceleration sensor chip.
 12. The method as set forth in claim 4,wherein the protrusion includes three linear elements.
 13. The method asset forth in claim 4, wherein the protrusion includes four linearelements.
 14. The method as set forth in claim 8, wherein thechip-holding surface of the collet extends along an outer periphery ofthe acceleration sensor chip.
 15. The method as set forth in claim 8,wherein the protrusion includes three linear elements.
 16. The method asset forth in claim 8, wherein the protrusion includes four linearelements.
 17. The method as set forth in claim 8, wherein theacceleration sensor chip has a square or rectangular shape, and theprotrusion includes four edge protrusion parts disposed along four edgesof the acceleration sensor chip, respectively.
 18. The method as setforth in claim 17, wherein the collet applies the negative pressure ontothe four edges of the acceleration sensor chip.